Spray machine



L. E. PITNER SPRAY MACHINE Nov. 12, 1940.

Filed Oct. 18,, 1937 3 Sheets-Sheet 1 &4 WW

N 1940- L. E. PITNER SPRAY MACHINE Filed Oct. 18, 1937 3 Sheets-Sheet 2 Nov. 12, 1940. PITNER SPRAY momma Filed Oct. 18, 1957 3 Sheets .5 3

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f/ay/ Patented Nov. 12, 1940 UNITED STATES PATENT OFFICE smv momma Lloyd E. Pltner, Milwaukee, Wis.

Application mm- 18, 1937, Serial No. 189,580 18 Claims. (01. 299-41) My invention relates to spray machines'and more particularly to those machines adapted to distribute liquid insecticides.

One of the primary objects of my invention is to provide a spray machine including an im proved compact, mobile unit adapted to be conveniently transported from place to place whereby it may be used to spray pest infected fields throughout a large territory.

During its use in the field the spray machine utilizes a spray rig arrangement including spray booms, these booms, for economy, being long, thereby permitting a maximum area to be sprayed per unit of movement of the machine.

However, due to their great length, these booms are cumbersome and not well adapted to withstand ordinary road travel from place to place when in their extended, spraying position. Consequently, in order to adapt my spray machine to road travel and to eliminate strain and injury to the spray rig mechanism during road travel,

and as another object of my invention, I have provided an improved boom and boom supporting arrangement which is adapted to be folded into a compact unit, suitable for road travel with a minimum of effort and without complicated folding operations on the part of the operator. Furthermore, the essential control of the unit may be had from a single operators station.

Still another object of the invention is to provide an improved device of the above class in which both the spray rig and booms are freely and independently movable to be adapted to the contour of the land being sprayed, this movement of the rig and booms also being brought about by a minimum of effort on the part of the operator and also being controlled by an extremely simple operating mechanism located at the single operator station.

Another object of my, invention is to insure uniformity of distribution of the spray solution by providing a truck speed indicator, a spray circuit pressure indicator and a spray circuit 45 control valve all together at an operators station whereby the operator can control the spray feed in accordance with changes in truck speed, to maintain the amount of insecticide fed constant per unit of area of the field.

Still another object of the invention is to provide a spray liquid pressure circuit arrangement wherein the pressure in said circuit may be utilized for adjusting the position of the booms, the position of the rig and for folding the booms.

55 Other objects and advantages of my invention will be apparent from the following description and accompanying drawings, in which:

Fig. 1 is a diagrammatic side elevation of the spray mechanism mounted upon a truck with the booms folded in readiness for road travel; 5

Fig. 2 is a diagrammatic rear elevation of the spray mechanism mounted on the truck with the booms unfolded to a position in readiness for the spraying operation;

Fig. 2A is a fragmentary view of the hydraulic 10 controls for lifting the booms;

Fig. 3 is a rear view of the spray rig proper, showing the manner in which the control for the spray liquid circuit is mounted thereon and connected therewith;

Fig. 4 is a view taken on line 4-4 of Fig. 3;

Fig. 5 is a plan view of the spray rig proper with the booms in unfolded position;

Fig. 6 is a view taken on the line 6--6 of Fig.

4; and 20 Fig. '7 is a perspective view of the liquid pumping apparatus showing the liquid circuits connected thereto.

It is understood that the embodiment disclosed herein is a preferred form and is for illus- 5 trative purposes only, being adaptable to change without departing from the spirit and scope of the invention set out in the appended claims.

Referring to the drawings, particularly Fig. 1, the entire spray assembly is shown mounted on 30 the rear platform of a truck and comprises generally a boom supporting and carrying assembly A (hereinafter referred to as the spray rig), a liquid pressure system B (shown in detail in Fig.

7) a liquid supply tank C, and a circuit control 35 unit D (shown in detail in Fig. 6). Conduits, hereinafter to be described in detail, conduct liquid from the supply tank to the pressure system and other conduits lead from the latter system back to the tank, this combination of circuits comprising the circulating and agitating system. Conduits are also provided to conduct liquid under high pressure from the pressure system to the control unit and thence through the boom outlets to the atmosphere. These circuits 5 constitute the liquid delivery system.

In order to attain compactness by folding whereby my spray rig may be adapted for road travel, I provide generally a pivotable boom supporting structure into which the booms which extend beyond the confines of the supporting structure may be folded, while the entire supporting structure itself may then be folded forwardly upon a truck or carriage upon which the rig is mounted. In order to provide vertical adjustof with respect to the tops of the plants being sprayed, I provide a supporting structure which is vertically adjustable with respect to the truck or carriage upon whichit is mounted. In the present embodiment the supporting structure for the booms comprises a lower horizontally positioned set of struts II), a pair of upright struts II each having its lower end secured to the forward end of the adjacent strut III (the forward strut I0 being located directly beneath a cross bar I2 in Fig. 5). The upper cross bar I2 to which the upper ends of the upright struts II are connected has secured thereto the upper ends of lean-to struts I3, the lower ends of which are secured to the rearmost laterally extending strut III.

The spray boom is shown herein as comprising three sections, a central section I4 and. a pair of laterally extending side sections I5, each having suitable spray nozzles I and I50. therein respectively. The section I4 extends between and is secured to substantially the center point of each of the longitudinal struts I0 while the side sections I5 are secured by swivel joints I 6 to substantially the same point of said struts Ill. By virtue of these swivel joints, free, independent movement of the boom sections I5, presently to be described, may be had, to maintain them parallel to the ground adjacently below, throughout the travel of the vehicle over undulated land.

This boom supporting structure comprising struts I0 and II, crossbar I2, and struts I3, is movable vertically to regulate the height of .the booms in accordance with the height of the plants being sprayed, and, as shown in the present embodiment, the struts II extend through suitable slidaweys Ila. in which the struts II are'vertically movable. These slideways are mounted on the upright elements of a rectangular frame comprising upright elements IIb and transverse elements No, this frame being in turn pivotally mounted on the upright standards H which are rigidly secured to the rear end of the truck platform. Thus it will be seen that adjustment of the vertical position of struts I I in slideways I la will cause like vertical adjustment of the position of struts III and cross bar I2 along with the appended booms I4 and I5.

The booms I5 are supported against excessive horizontal movement in such a manner that they are held substantially non-rigidly in the positions shown in Figs. 2 and 5. Being so supported, they are not subject to breakage and undue strains if, by accident, they should strike a fence post or the like and be shifted horizontally rearward about universal joints I6. To provide such a support, there are embodied herein elevating cables 22, the operation of which will be described in detail presently. These cables extend from the upper part of the spray rig downwardly to the about center of the booms I5. Suitable fasteners I8 are mounted on the booms I5 and have the lower ends of cables 22 fasteners I8. From the above it will be seen that 7 2,221,433 .ment for the boom to regulate the height thereshould the boom I5 strike some stationary object as the vehicle moves forwardly they will move about the joint in an arc rearwardly and upwardly until the object has been passed.

As above described. the boom supporting structure is mounted on the truck by uprights I! in such a manner that it may be pivoted forward in a body to form a compact unit suitable for road travel. In the present embodiment this is accomplished by pivoting the rectangular frame IIb--I lo, the boom supporting structure and the booms on uprights II at the end of the truck platform about suitable securing pins I6b into a position shown in Fig. l. The spray rig may then be secured in this position by suitable anchor wires, one of which is shown at to.

To the end that the booms I5 may be raised and lowered in accordance with changes in the contour of'the land and also that they may be folded for. road travel, I provide the cables 22, the outer ends of which are anchored at the approximate centers of booms I5. Each of these wires 22 extends upwardly and over one of the pulleys 23 mounted on each end of cross piece I2 beneath a guard 23a, inwardly along said cross piece to about the center thereof, and down and around one of the pulleys 24 rotatably positioned beneath the guards 25. The ends of wires 22 adjacent pulleys 24 are suitably anchored to the cross piece as at 25.

Each of the pulleys 24 is rotatably mounted on the end of a piston rod 21 adapted to be shifted longitudinally of the cross piece I2 by pressure exerted within each of the cylinders 28 inwhich the rods 21 and their respective pistons are adapted to reciprocate. Thus it will be seen that with such a construction any increase of pressure within one or both of the cylinders 28 will cause outward movement of one or both of the pulleys 24 with respect to its cylinder, thereby taking up the length of one or both of the wires 22 over pulleys 23 to raise one or both of the booms I5 (see Fig. 2A). On the other hand, release of pressure in either of the cylinders 28 will permit movement of the pulley 24 associated therewith inwardly toward the respective cylinder 28, which movement will let out a proportionate length of the associated wire 22 to permit the respective boom I5 to be lowered. In the construction shown herein the length of piston rods 21 is such that in folding the booms hydraulically they are moved only to an angle ofslightly over and then the remaining movement is by hand. It will be readily understood that the entire folding movement may be accomplished hydraulically by the provision of a suitable system of pulleys in place of the pulleys 24.

A third cylinder 29 is shown herein mounted in a vertical position upon the upper transverse elements I Ic of the pivotal rectangular frame. This cylinder has a piston rod 30 extending upwardly therefrom, the upper end of which is suitably secured to the cross .piece I2 and it will be readily understood that changes in pressure within the cylinder will cause vertical movement of the rod 30, cross piece I2 and its appended parts, namely, struts II, I 0, and booms I4 and I5, relative to the rectangular frame and truck platform. v

From the foregoing it will be seen that I have provided a boom and boom supporting arrangement wherein height of the entire boom structure can be adjusted vertically by regulating pressure in the cylinder 29; wherein the side booms may be adjusted angularly with respect to the ground by regulating pressure in cylinders 26; wherein the side booms may be folded into the supporting structure by pressure in cylinders 28, and wherein the folded booms, with the supporting structure may be folded from a working position over the end of the truck to a position above the truck to provide a compact unit suitable for road travel.

To the end that the contents of tank C may be agitated at all times, I have provided herein a pair of liquid pressure circuits. One is adapted to deliver liquid from the tank to the booms while the other operates simultaneously in parallel with said circuit to return liquid to the tank.

Referring now to Figs. 1 and '1, the supply tank C has pipes 3| and 32 extending longitudinally through the top and bottom respectively thereof. The pipe 3| has three series of holes therein, two series being directed toward the sides of the tank while another is directed downwardly. With such an outlet arrangement in the pipe 3| maximum agitation of the contents of the tank is obtained due to the flow of the incoming liquid down and across under the directing influence of the curved sides. This pipe consti-tutes the liquid inlet for the tank and is connected with conduit 33 to the circulating and agitating circuit of the pressure system to be described presently, while pipe 32 constitutes the outlet of the tank and is connected with a conduit 34 (herein designated as the main draw-off) to a liquid delivery circuit and to said circulating and agitating circuit of the pressure system.

The pumping arrangement shown in the present embodiment comprises a motor 35 which has a drive shaft 36 connecting with and driving a suitable high pressure pump 31. The shaft 36 has a drive pulley 38 mounted thereon which, through a belt 39 and a drive pulley 40, actuates a low pressure pump 4|. The motor and pumps are suitably mounted on a truck platform shown herein by securing means such as angle bars 42.

The above mentioned circulating and liquid delivery circuits as heretofore explained, are adapted to operate in parallel under the influence of the pumps 31 and 4|, the delivery circuit comprising conduits 52 and 53 and the circulating circuit comprising conduits 58, 46, 46, and 41.

In order than tank C may be filled with liquid, the pump 4| is operated by motor 35 as above described and the inlet end (not shown) of a conduit 43 is connected with a suitable liquid.

reservoir. By manipulation of the handle of a two-way valve shown at 44, conduits 45 and 46 are placed in direct communication through valve 44. As the pump 4| operates, it draws liquid through conduits 43, 45, 46, and forces it out of a conduit 41 (which serves as the outlet of pump 4|) into conduit 33 from whence it passes into the tank C through pipe 3|. It is to be understood that if desired this filling operation may proceed during the function of the delivery circuit. When the filling operation is completed, the handle of valve 44 is reversed to place conduits 46 and 48 in communication, leaving conduits 43 and 45 entirely out of the liquid circuit.

The system is now in readiness for delivering liquid to the booms under the action of the high pressure pump 31, by which liquid is drawn from the tank through pipe 32, conduits 34, 49, and 50 (conduits 49 and 5|] being designated the high pressure draw-oil) and then ejected under high pressure into the delivery system which comprises conduits 5|, 52, and 53. Liquid passing through conduit 53 flows to the booms through a control system presently to be described. Connecting with this high pressure liquid delivery system (shown shaded in Fig. 7) are overflow conduits 54 and 55 and a relief, valve 56 set, under normal conditions, at any convenient pressure. The intermittent overflow from conduits 54 and 55 occurring when the delivery pressure exceeds this point, passes into a conduit 51 and thence into the circulating and agitating system, (shown as unshaded conduits).

While the delivery circuit functions as above described, the agitating and circulating circuit is being independently operated by pump 4|. This circuit comprises a low pressure draw-off which includes conduits 58, 48, and 46, and return conduits 41 and 33, the latterconnecting with pipe 3| in the tank C. It will be seen that when both pumps are effective and the valve 44 is manipulated to shut conduits 43 and 45 out of the system, the delivery circuit and the circulating circuit, as previously stated, operate in parallel. Thus while the delivery circuit is functioning to draw ofi liquid from the main draw-off conduit 34 for transmittal to the booms, the circulating circuit is also withdrawing liquid from conduit 34 to be returned to the tank C and, as previously stated, the effectiveness of the latter circuit for agitating the contents of the tank is not dependent upon excess pressure existing in the delivery circuit to create overflow.

To the end that the vertical position of the spray rig, the angle of the side booms I5 and the amount of liquid spray fed to the booms may be controlled, I provide the preferred control circuit shown in Figs. 3 and 6.

Referring to Fig. 3, a. preferred control circuit is shown, mounted on the crosspiece |6d by brackets l6e, one of which is shown in Fig. 4, the crosspiece is in turn welded as at l6g to uprights H on the rear of the truck platform. The control circuit consists of an inlet conduit 59 which is connected by conduit 60 (Fig. 1) to the outlet 53 of the pressure system and extends upwardly, having a branch 6| extending therefrom. Liquid under pressure created by pump 31 flows from branch 6| to the booms l4 and |5| 5 through boom shut-off valves 62, 63, and 64 and conduits 65, 66 and 61 connected thereto, respectively. The feed of liquid under pressure, through the conduit 59 and branch 6| and through the flexible conduits 65, 66 and 61 to the respective booms may be individually controlled by independent operation of shut-oil valves 62, 63 or 64 or jointly by the operation of a master valve shown at 68.

Under normal operating conditions the high pressure delivery pump 31 operates at a constant rate, thereby creating constant liquid pressure in the delivery circuit, and since, under circumstances presently to be described, it is necessary to control the volume of liquid discharged into the atmosphere through the booms, it is necessary to provide an overflow circuit for that portion of the liquid which periodically exceeds the requirements of the booms. This overflow circuit is shown herein as including that portion of conduit 59 which extends upwardly of the junction of the delivery branch 6|, transverse conduit 69 having a pressure control valve 690 therein, and the downwardly and transversely extending return conduit 10. This return conduit in turn connects with a flexible pipe 1| (Fig. 1) which leads to an inlet 12 located at the bottom of tank C. Thus it will be seen that under the influence of the pump 31 liquid is forced through the delivery system into the conduit 58 and thence through conduits 68, 10, and H back through the inlet 12 of the tank, and that by operation of the pressure control valve 68a,the pressure of the liquid in the entire delivery system and hydraulic system, to be described presently, will be regulated.

The amount of insecticide sprayed per area of field is a function of the pressure in the delivery system and the speed of the vehicle upon which the spray mechanism is being moved. To the end that a predetermined, uniform quantity of the insecticide may be sprayed over a given unit of field area and may be maintained uniform throughout unavoidable changes in speed of the vehicle, and in order that this uniformity maybe maintained by an operator without interrupting the spraying operation, I have provided, and disclose herein, a preferred arrangement of indicating and manipulating mechanism. In the present embodiment this arrangement comprises a pressure gauge 13 which is: responsive to pressure changes in the delivery system through a conduit 14 and which taps the delivery circuit through the conduit 58. A speedometer 1311 which registers the speed of the vehicle, through suitable connections with a moving part of the vehicle (not here shown), is located adjacent the pressure gauge. The gauge 13 and speedometer 13a may be mounted in any suitable manner and in the present embodiment are shown secured by brackets 15 to the cross piece l6d.

Assuming that the vehicle is traveling over the plants to be sprayed at a given rate, and that the pressure gauge indicates a given pressure, which combination of speed and pressure results in the desired distribution of insecticide over the field, the operator merely observes the changes in vehicle speed in the speedometer and regulates the pressure in the delivery line proportionately by manipulating valve 6811, thereby maintaining constant the quantity of liquid distributed per unit area of field.

As previously described, the entire boom structure may be shifted vertically by creating pressure changes in a cylinder 28, and side booms l5 may be adjusted vertically by creating pressure changes in cylinders 28. Means is provided herein for creating these pressure changes in the cylinders by utilizing the normal pressure existing in the liquid delivery circuit. As shown herein, a pressure by-pass system 18 extends from the top of conduit 58 to the top of conduit 10. A bank of three two-way valves 18, and 8| is mounted on this by-pass system 18, each valve having an operating lever 19a, 80a, and 8|a respectively. Connecting with the valves are flexible conduits 82, 83 and 84 respectively.

The conduits 82 and 84 have their ends remote from the valves I8 and ill connected to the outer end of each of the cylinders 28, while the conduit 83 is similarly connected with the bottom of the cylinder 29. During the operation of the pump 31 the pressure existing in the delivery circuit will of course exist likewise in the system 18. By manipulation of the handles of the twoway valves 19, 88 or 8|, conduit 59 is placed in communication with conduits 82, 83 and 84 through 19b, 80b and 8|b and valves 19, 80 and 8|. Under these circumstances pressure in the liquid delivery system is transmitted to cylinders 28-28 and 28, thereby raising the rig and booms. When the rig and booms have been raised to the desired position by the above manipulation of the valves, the handles of the latter are again moved to a neutral closed position to cut oil communication between conduit 69 and the valves. When the handles are in this closed position the conduits 82, 88 and 84 are also cut oil from communication with the valves and the pressure then existing in the cylinders 28-28 and 29 is maintained to hold the rig and booms in the desired position. Should the operator now desire to move the rig or booms down, he again mani ulates the valve handles into a third position. In this position communication between pressure conduit 59 and the valves is still cut off but communication has been established between the conduits 82, 83 and 84 and liquid return conduits H0, 880 and 8|c. Under these conditions the accumulated pressure in the cylinders is released by the return flow of liquid from the cylinders through conduits 82, 83 and 84, the valves, return conduits 18c, 80c and 8lc, return conduit 18a, conduits l8 and II to pipe 12 in tank C. It will be understood that this release of liquid permits the rig and boom to fall by gravity until the operator again moves the valve handles to either the neutral cut oil position or the first described raise position. It will be further understood that the rig and booms may be regulated independently by independent movement of the valve handles 19a, 880. or 8|a.

Briefly the operation of my spray mechanism is as follows: Assuming the spray rig to be in the position shown in Fig. 1, that is in its folded position in readiness for road travel, the anchor rod |6c is disconnected and the boom structure is then swung into a position shown in Figs. 3 and 4 about the pivot lib. The operator then manipulates the valve levers 19a, 88a and Ma into a position to establish communication between the cylinders and conduits 19c, 80c and Me and thebooms |5 along with the boom supporting structure, which includes struts II), II, l3 and cross piece I 2, assume the position shown in full lines in Fig. 2.

It is to be particularly noted at this point that I have provided herein a novel priming arrangement which comprises a conduit 4|a which taps the conduit 54 of the high pressure system and injects liquid under the high pressure of the latter system into the conduit 46 of the low pressure system which serves as the inlet for the pump 4|. A section 4|b of the conduit 4|a extends into and longitudinally of the conduit 46. The control of the flow of liquid from the conduit 54 to the conduit 46 through conduit 4|a is obtained by manipulation of a suitable valve 4|c. In effect liquid is conducted by the conduit 4| (1 at high pressures from the conduit 54 into and longitudinally of the conduit 48 and in the direction of the low pressure pump 4|. Under these conditions primingliquid for the pump 4| is drawn from the tank through conduits 34, 58, 48, and 46 in sufflcient quantities to prime the pump 4| during the starting of the pressure system.

To start the mechanism it is first necessary for the operator to transfer a small quantity of solution, about a bucket full, into the bottom of the tank. The motor 35 is then started, whereby operation of the pumps 31 and 4| takes place. At this time the valve 4 la is manipulated to bring the conduit 4|a into operation whereby pressure developed by the pump 31 causes the injectorpriming operation to take place. The operator then manipulates the lever 44 to connect conduits 43 and 45 with the conduit 48 of the pump 4|. This pump now having been primed proceeds to withdraw solution from the main reservoir through conduits 43, 45 and 46 and'conduct it to the tank through outlet conduits 41 and 33-. This particular pumping operation is continued until the tank on the truck has been filled with solution, at which time the lever 44 is manipulated to disconnect conduits 43 and 45 and bring conduits I4, 58, and 48 into operation. The operator, who is stationed on the truck platform at the various controls hereinbefore described, has closed valve 6! to shut off the booms during the filling operation and has opened the valve 69a located in the transverse conduit 69, whereby pressure created in the delivery circuit by the pump 31 forces the liquid down through the return conduit 10 and into tank C through inlet I2 rather than through the branch GI and into the booms. The filling operation having been completed, the operator then opens the valves ii and 69a.- and the liquid delivery circuit now becomes effective to deliver insecticide to the booms. It will be readily understood that the pressure available to deliver insecticide into the atmosphere through the booms may be controlled by the valve 69a, and in order that the priming operation be eflective this valve must be at least partially closed until that operation is completed.

As previously explained, the high pressure delivery circuit connected with the pump 31 and the low pressure circulating circuit connected with the pump 4| are adapted to operate simultaneously, whereby the contents of tank C are continuously circulated and agitated throughout the operation of the spray mechanism.

Assuming that the operator has determined the proper readings on the pressure gauge I3 and speedometer 13a which will give a predetermined quantity of liquid to be distributed per unit of field area, he then watches the dials and regulates the valve 69a in accordance wtih the variations in the reading on the speedometer 13a.

Should variations in the contour of the land being sprayed occur, the booms l5 may be independently hydraulically regulated through cylinders 28-28 to compensate for these variations by manipulation of the valve levers 19 and 8|. In the event that wind conditions or varying height of the plant require the height of the boom structure to be regulated, this may also be accomplished hydraulically by actuation of cylinders through the valve lever 80. After a field has been sprayed and it is desired to transport the apparatus to a different territory, the entire boom structure may be raised by the previously explained manipulation of the valve 80, and the side booms [5 may be drawn into their folded position by the wires 22 through the previously described manipulation of the valve levers l9 and Ill preparatory to the folding of the entire boom structure over the end oi. the truck into a position shown in Fig. 1.

Having thus described my invention, what I desire to secure by United States Letters Patent is:

1. In a spray machine, spraying mechanism, a platform for mounting said spraying mechanism, said spraying mechanism including a frame having upright elements, a standard on said platform for supporting said frame by pivotal engagement with said upright elements whereby said frame and its appended parts may be pivotally moved on said standard to be folded over said platform, a boom structure mounted on said frame to move vertically thereof in its entirety,

booms in said boom structure mounted to extend beyond the confines thereof and having pivotal attachment with said structure at their inner ends, a liquid supply for said spraying mechanism, a pressure system for transmitting liquid under pressure from said supply to said spraying mechanism, independent hydraulic motors each having a driven member, each of said members being operatively connected respectively with each of said pivoted booms and with the vertically movable boom structure to adjust the position of said booms upon operation or the respective motor, an operating valve for each of said motors, pressure conduits from each of said motors to said pressure system.

2. In a spray machine, spraying mechanism, a platform I01 mounting said spraying mechanism, said spraying mechanism including a boom structure, means on said platform for supporting said boom structure for vertical movement with respect to said platform, said boom structure including booms mounted to extend beyond the confines thereof and having pivotal attachment with said structure at their inner ends, a liquid supply for said spraying mechanism, a pressure system for transmitting liquid under pressure from said supply to said spraying mechanism, independent hydraulically operating means connected with said pivoted .booms and with the vertically movable boom structure, operating valves for said hydraulically operating means, pressure conduits from said valves to said pressure system.

3. In a spray machine, spraying mechanism, means for mounting said mechanism, said mechanism including a boom structure supported by said mounting means, said structure being movable in its entirety with respect to said mounting means, a liquid supply for said spraying mechanism, a pressure system for transmitting liquid under pressure from said supply to said spraying mechanism, a hydraulic motor for said boom structure, a pressure actuated element in said motor, said element being operatively connected with said boom structure for moving the same upon operation of the motor, an operating valve for said motor, a pressure conduit from said motor to said pressure system.

4. In a spray machine, spraying mechanism, means for mounting said mechanism, said mechanism including a plurality of spray distributing booms carried by said mounting means and secured thereto by pivotal means at adjacent ends of the boom, a liquid supply for said booms, a pressure system for transmitting liquid under pressure from said supply to said booms, independent hydraulic motors associated with each of said booms, pressure actuated elements in said motors, means for operatively connecting each element with a boom for moving the same pivotally upon operation of the respective motor, pressure conduits from said motors to said system and valves in said conduits for controlling the pressure transmitted to said motors.

5. In a mobile liquid insecticide spraying unit, a platform, an insecticide supply tank, a pressure system, a hydraulic control circuit and an insecticide dispensing system mounted on said platform, conduits connecting said supply tank and said pressure system, conduits connecting said pressure system and said control circuit, and conduits connecting said control circuit and said dispensing system, said pressure system being adapted to withdraw insecticidal liquid from said tank and deliver it to said dispensing system through said control circuit under pressure, said dispensing system including a boom structure movable bodily with respect to said platform and booms pivotable on said boom structure, a bypass in said control circuit, a plurality of valves in said by-pass, a hydraulic motor for said boom structure, a pressure actuated element in said motor, said element operatively connecting with said boom structure for moving the same upon operation of the motor, a plurality of hydraulic motors, pressure actuated elements in said motors, means for operatively connecting each of said elements with a boom for moving the same pivotally upon operation of the respetcive motor conduits from said valves in said by-pass to each of said respective motors, said last named conduits being adapted to transmit operating pressure in said control circuit to said hydraulic motors upon manipulation of the respective valves.

6. In a liquid insecticide spraying unit, an insecticide supply tank, a liquid pressure system, a hydraulic control circuit and an insecticide dispensing system, conduits connecting said supply tank and said pressure system, conduits connecting said pressure system and said control circuit and conduits connecting said control circuit with said dispensing system, saidv pressure system being adapted to withdraw insecticidal liquid from said tank and deliver it to said dispensing system through said control circuit under pressure, said dispensing system including 'pivotally mounted booms, valve means in said control circuit, means operated by hydraulic pressure and connected with said booms, said pressure operated means being operable to shift the position of said booms about the pivots thereof and pressure conduits between said valve means and said hydraulically operated means.

7. In a liquid insecticide spraying unit, an insecticide supply tank, a liquid pressure system, a hydraulic control circuit and an insecticide dispensing system, conduits connecting said supply tank and said pressure system, conduits connecting said pressure system and said control circuit and conduits connecting said control circuit and said dispensing system, said pressure system being adapted to withdraw insecticidal liquid from said tank and deliver it to said dispensing system through said control circuit under pressure, said dispensing system including a boom structure movable in its entirety with respect'to the spraying unit, valve means in said control circuit, a hydraulic motor for said boom structure, a pressure actuated element in said motor, said element operatively connecting with said boom structure for moving the same upon operation of the motor, a conduit from said valve means to said mtor.

B. In an insecticide spraying machine, a liquid insecticide supply, a liquid dispensing system comprising movable booms, a pressure system between said supply and said dispensing system for transmitting liquid under pressure from said supply to said dispensing system, pressure responsive means operatively connected with said boomsto move the latter upon pressure changes, and means for transmitting pressure in said pressure system to said pressure responsive means.

9. In a spray machine, a spray rig, a boom supporting structure, said boom supporting structure being movably mounted on said spray rig for vertical movement relative thereto, means for moving said supporting structure through its vertical movement, said means including a hydraulic motor mounted on said rig and having an actuating element operatively connecting. with said structure, booms mounted on said structure for pivotal movement relative thereto, means for moving booms through their pivotal movement, said means including, hydraulic motors mounted on said structure and means for operatively connecting said actuating elements with said booms.

10. In a mobile insecticide applicator, a vehicle, a rig mounted on the vehicle, said rig including a rectangular frame mounted for pivotal movement about one end of the vehicle, the horizontal elements of said frame comprising slideways, a boom supporting structure carried by said frame, said structure including vertical elements adapted to cooperate with said slideways, said structure being adapted to be moved vertically with respect to said vehicle and said frame, booms on said structure, said booms being pivotally secured thereto, being extensible beyond the confines thereof to cover a wide area of the field to be sprayed during movement of the vehicle, and being foldable into the confines of said structure about said pivots.

11. In a mobile insecticide applicator, a vehicle, a rig mounted on the vehicle, said rig including a boom supporting structure mounted for pivotal movement about the end of the vehicle, said supporting structure including uprights secured to said vehicle for vertical movement relative thereto, booms carried by said structure and having pivotal connection therewith, said booms being extensible beyond the confines of said structure and being foldable into the confines of said structure about the pivots.

2. In a spray machine, a boom supporting structure, booms mounted on said structure by universal joints at their inner ends, elevating cables secured to said booms and extending upwardly thereof, means for withdrawing and letting out said cables to control the vertical, angular position of the booms, said booms being mounted to swing freely rearwardly about said universal joints.

13. In a spray machine, a. boom supporting structure, booms mounted on said structure by universal joints, means for supporting said booms in an extended position outwardly from said structure and means for securing said booms against forward horizontal movement about said universal joints.

14. In a spray machine, a boom supporting structure, booms mounted on said structure by universal joints, elevating cables secured to said booms and extending upwardly and inwardly to said boom structure, a guy wire for each said boom having one end secured to the adjacent boom, extending rearwardly and having its other end secured to said structure to restrict forward movement of said boom about said universal joints. I

15. In a spray machine having a liquid supply, boom supporting mea'ns, booms movably mounted on said supporting means for movement from an extended, operative position to a folded position, conduits connecting said liquid supply with said booms, means for propelling liquid under pressure fromsaid supply to said booms and hydraulic motors associated with said booms, said motors having actuating elements, means for operatively connecting said elements with said booms to move the same from an extended to a folded position upon operation of the respective motor, the combination of a control circuit interposed in said conduits, said control circuit having pressure conduits connecting said motors therewith, valves associated with said circuit for controlling the pressure in said pressure conduits and pressure indicating means operably connected with said control circuit and located in the vicinity of said valves.

16.. In a mobile spray machine having a liquid supply, boom supporting means, booms movably mounted on said supporting means for movement from an extended, operative position to a folded position, conduits connecting said liquid supply with said booms, means for propelling liquid under pressure from said supply to said booms and hydraulic motors associated with said booms, said motors having actuating elements, means for operatively connecting said elements with said booms to move the same from an extended to a'folded position upon operation of the respective motor, the combination of a single control circuit interposed in said conduits having pressure conduits connecting said motors therewith, valves in said circuit for controlling the pressure in said pressure conduits, another valve in said circuit for controlling the flow from said supply to said booms, pressure indicating means operably connected with said control circuit and located in the vicinity of sail last named valves and speed indicating means mounted in the vicinity of said first named valve.

17. In a spray machine, a boom supporting structure, uprights, a cross piece at the top of said uprights, said uprights having boom securing means at the lower ends thereof, booms so pivotally secured to said boom securing means that they may be moved vertically, power actuated operating elements mounted on said cross piece, and means connecting said operating elements and said booms for adjusting the angular position of said booms about the pivots upon actuation of said operating elements.

18. In a spray machine, the combination of a boom supporting structure, booms on said structure, connections for securing said booms, to said boom supporting structure, including a rearwardly operating hinge connection between the inner end of said boom and said supporting structure, and means for operatively securing said boom in a laterally extended position with respect to said machine to afiord rearward horizontal, pivotal movement of said boom when the latter strikes obstructions as said machine moves forwardly thereby.

LLOYD E; PITNIB. 

